Split 3 of the lemons in half lengthways and remove the flesh.
Pass the flesh through a sieve and measure out around 110ml, reserving it in a bowl.
In a saucepan, add 500ml whipping cream, 120g white sugar, and the zest from the 4th lemon. Bring to a simmer and reduce slightly until it coats the back of a spoon.
Pour the mixture back into the lemon shells and chill in the fridge for 6 hours or overnight.
Top with brown sugar and use a torch to melt/brown it.
Serve once the sugar has set hard.
